@Resource
GatewayValidator gatewayValidator;

@RequestMapping(value = "/gateway/signup", method = RequestMethod.POST)
public ApiResponse signup(@Valid Gateway gateway, BindingResult result) {
    ApiResponse rspResult = new ApiResponse();
    gatewayValidator.validate(gateway, result);
    if(result.hasErrors()){
        rspResult.setCode(ApiCode.PARMAS_ERROR);
        rspResult.setMessage(BaseUtils.GetValidErrorMessage(result));
    }
    else {
        //do something
    }
    return rspResult;
}

package smarthome.api.models;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.lang3.time.DateUtils;
import org.hibernate.validator.constraints.NotEmpty;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class Gateway extends BaseClass implements Serializable {
    
    /**
     * None
     */
    protected String vendorCode;
    /**
     * None
     */
    protected String productCode;
    /**
     * None
     */
    @NotEmpty(message = "序列号不能为空")
    protected String serialNumber;

    public Gateway() {
    }
    
    public String getVendorCode() {
        return vendorCode;
    }
    public void setVendorCode(String vendorCode) {
        this.vendorCode = vendorCode == null ? null : vendorCode.trim();
    }

    public String getProductCode() {
        return productCode;
    }
    public void setProductCode(String productCode) {
        this.productCode = productCode == null ? null : productCode.trim();
    }

    public String getSerialNumber() {
        return serialNumber;
    }
    public void setSerialNumber(String serialNumber) {
        this.serialNumber = serialNumber == null ? null : serialNumber.trim();
    }
}

package smarthome.api.validators;

import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;

import javax.annotation.Resource;
import java.util.List;

@Component
public class GatewayValidator implements Validator {
    public boolean supports(Class clazz) {
        return Gateway.class.equals(clazz);
    }
    public void validate(Object target, Errors errors) {
        Gateway gateway = (Gateway) target;
        if(gateway.getGatewayId() == null && StringUtils.isEmpty(gateway.getSerialNumber())){
            errors.rejectValue("gatewayId", null, "网关编号和序列号不能同时为空");
            errors.rejectValue("serialNumber", null, "网关编号和序列号不能同时为空");
        }
    }
}

package smarthome.api.validators;

import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;

import javax.annotation.Resource;
import java.util.List;


@Component
public class GatewayValidator implements Validator {
    @Resource
    private ModuleValidator moduleValidator;
    public boolean supports(Class clazz) {
        return Gateway.class.equals(clazz);
    }
    public void validate(Object target, Errors errors) {
        Gateway gateway = (Gateway) target;
        if(gateway.getGatewayId() == null && StringUtils.isEmpty(gateway.getSerialNumber())){
            errors.rejectValue("gatewayId", null, "网关编号和序列号不能同时为空");
            errors.rejectValue("serialNumber", null, "网关编号和序列号不能同时为空");
        }
        for(Module module : (List<Module>)gateway.getModuleList()){
            ValidationUtils.invokeValidator(moduleValidator, module, errors);
        }
    }
}

package smarthome.api.validators;

import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;

import javax.annotation.Resource;

@Component
public class ModuleValidator implements Validator {
    @Resource
    private IModuleService moduleService;
    public boolean supports(Class clazz) {
        return Module.class.equals(clazz);
    }
    public void validate(Object target, Errors errors) {
        Module module = (Module) target;
        if (StringUtils.isEmpty(module.getSerialNumber())) {
            errors.rejectValue("serialNumber", null, "模块序号不能为空");
        }
        else {
            if(moduleService.getFirst(module.getSerialNumber()) != null){
                errors.rejectValue("serialNumber", null, "模块序列号已经存在");
            }
        }
    }
}